When a seller of an item creates an advertisement to be included in a listing of items for sale on a network-based publication system (e.g., EBAY®, AMAZON®, or CRAIGSLIST®), the seller may include information about the item in the advertisement. The information may include a title of the item or a description of the item. Furthermore, the seller may be allowed to select media data for inclusion in the advertisement. Examples of media data include an image (e.g., an image file) and a motion picture (e.g., a video file). Despite allowing the seller to select the media data for inclusion in the advertisement, an operator of the network-based publication system may retain control over whether the media data is published on the network-based publication system (e.g., included in the advertisement) for public viewing.